Signal storage in telegraph printer systems



SIGNAL STORAGE IN TELEGRAPH PRINTER SYSTEMS Original Filed Sept. 1'7, 1940 INVENTOR. JflMEJ H. JPf/VCE? Patented Dec. 7, 1943 SIGNAL STORAGE IN TELEGRAPH PRINTER SYSTEMS James A. Spencer, Teaneck, N. J., assignor to ,Radio Corporation of America, a corporation of Delaware Original application September 17, 1940, Serial Divided and this application May 27, 1941, Serial No. 395,334

Claims.

This invention relates to means for storing signals in single channel telegraph printer systems and is a division of my co-pending application, Serial No. 357,109, filed September 17, 1940. The channel may be either a wire or a radio link, as it is immaterial what connecting link is used between the transmitter andreceiver.

It is an object of the invention to obtain storage of telegraph signals in single channel printers to permit operation of the printer with use of a minimum number of electromagnetic relays.

Other objects will appear in the following description, reference being'had to the drawing, in which:

The single figure of the drawing diagrammatically illustrates the circuits of my invention at the printing station.

Referring to the drawing, the figure illustrates diagrammatically the circuits of my invention. In this circuit ground is understood to be connected to the center of the battery, of which the plus and minus terminals furnish the positive and negative voltage used in the system.

The signals from the transmitter coming over the connecting link arrive at line 52 and energize the coils of polar relay 53, one end of the coil of this relay being connected to the line and the other end to ground. The marking contact on this polar relay is connected to the positive terminal and the spacing contact is a blank. The tongue of the relay 53 is connected to the ring of distributor 54 having a segment for each signal code unit. The first one of the group of leading segments on the commutator of distributor 54 is connected through the coil of relay 55 to ground. The second and third one of this group of leading segments are similarly connected to relays 56 and 51 and ground.

Relay coil 55 has two pairs of switch contacts, one connecting the positive terminal to the holding coil of the relay and thence to ground through the normally closed contact of clearing relay 58. The other pair of switch contacts on relay 55 connects, when the relay is energized, segment 4 of the commutator of distributor 59 to one terminal of printer selector magnet No. 1, the other end being grounded. Relays 56 and 51 have switches for similarly closing their holding circuits, and switches for connecting segment 4 respectively through printer selector magnet No. 2 and No. 3 to ground.

The group of lagging segments 4, 5, 6 and '7 of the commutator of distributor 54 are connected respectively to printer selector magnets No. 4, 5, 6 and '7.

The ring of distributor 59 is connected to the positive terminal and segment No. 5 of the commutator of this distributor is connected through the operating coil 'of relay 58 to ground. Seg ment No. 7 of this commutator is connected to eighth pulse magnet No. 8 of the printer. All segments other than Nos. 4, 5 and 7 of distributor 59 are blank.

The printer intended to be used in the embodiment of this application is a seven unit printer disclosed in my co-pending application, filed J anuary 21, 1939, Serial No. 252,179. It is not necessary to complicate this disclosure by illustrating and describing this printer. It will be sufiicient to say that the signal pulses operate the proper ones of selector magnets No. 1 to 7 and cause their armatures to engage their selector bars, and that the eighth pulse magnet No. 8 causes the selected selector bars to move and align notches therein with the proper type bar and immediately thereafter to energize the printing magnet for causing this bar to strike the type on the platen.

Distributors 54 and 59 have brushes 6!], 6| for connecting their rings With the commutator segments, which run in synchronism with the brushes at the transmitter, not shown, so that the leading code units 1, 2 and 3 pass in succession through the leading commutator segments Nos. 1, 2 and 3 and the lagging code units 4, 5, 6 and '7 similarly pass through the lagging segments Nos. 4, 5, 6 and 7. Of course, the code units and their commutator segments may be differently grouped for similar operation, but the grouping given has been found to be quite satisfactory in practice.

The operation of my improved printer system will now be described:

The plus and minus pulses sent out by the transmitter come in over line 52 and throw the tongue of poler relay 53 to the right with a positive pulse and to the left with a negative pulse.

With a code combination for, say, the letter Y, positive pulses would be received in the first, third and sixth time period and negative pulses in the second, fourth, fifth and seventh period. A positive pulse would thus be received while brushes BI] and BI are on contacts No. 1 of the distributors. Positive current then flows through brush 50 to the operating coil of relay 55. Both of the switches of this relay then close. Positive current flows through the holding coil and the normally closed switch of relay 58 to ground. The other switch of this relay 55 is connected to contact No. 4 on distributor 59, so current cannot pass through this switch to the printer selector magnet at this time. is stored in relay 55.

When the brushes 60 and 6| reach segment No. 2 of their respective commutators, no current flows through distributor 54, because a negative pulse is received and the switch tongue of poler relay 53 is in engagement with the left-hand blank contact.

When the brushes reach segment No. 3, positive current is coming in over line 52 .and polar relay magnet 53 is energized to throw its switch tongue against the positive contact. This energizes relay 51, which closes the circuit of its holding coil through the normally closed contact of relay 58 and connects the coil of printer magnet No. 3 to contact No. 4. TheNo. 3 printer magnet is not energized at this time, but the unit is merely stored in relay 51.

When the brushes reach segment No. 4, no

Nevertheless, the signal current passes through distributor 54, as a nega-' tive pulse is coming in over line 52. However, brush 6| connects positive current to .the switch contacts of relays 55 and 5! and current immediately flows through the'closed switch contacts to magnets 1 and 3 to ground. The stored signals thus operate their respective magnets.

When the brushes reach segment N o. 5, no current flows through distributor 54, because the incoming pulse is negative, but the brush 6! on distributor 59 puts current through the operating coil of relay 58 and opens the holding circuit of relays 55 and 51, thus returning them to their normal condition ready for the next code combination,

When the brushes reach segment No. 6, positive current is coming in over line 52 and current fiows through brush 60 on distributor 54 directly to printer magnet No. 6, thus completing the selection for the letter Y.

When the brushes reach segment No. 7, :negative current is coming in over line 52 and no current passes through distributor 54, but current passes through brush 6| on distributor 59 to the No. 8 relay. This is commonly called the eighth pulse relay, which causes the printer selector .bars to be moved to the position demanded by the energization of printer selector magnets l, 3 and 6. The performance of the printing function then takes place and it can continue, if necessary, during the time that the brushes are on the first, second and third segments of the distributors, because the signals for the first three printer selector magnets, if selected, will be stored in relays 55, 56 and 5'! and do not require connection with printer selector magnets Nos. 1, 2 and 3 until the brushes reach the fourth segment of the distributors. Thus, at the receiver the storing of the first three units of the code combination gives ample time for the local printing function to take place and no time must be set aside for the performance of these functions.

In my invention it will. be seen that all of the circuit time is used in transmitting signals and the local functions at the receiver are performed while signals are being transmitted and received over the single channel.

Various changes in the embodiment of my invention may be made without departing from the spirit of my invention.

Having described my invention, what I claim is:

1. In a receiving system for multi-unit equal length codes, a distributor commutator having a signaling segment for each code 5 unit, a first group of printer selector magnets for the leading code units, a second group of printer selector magnets for the lagging code units, a plurality of relays having operating and holding coils and make contacts, a clearing relay having an energizing coil and break contacts, conductors connecting said holding coils to a source of potential through said break contacts, conductors connecting the leading segments of said distributor to said operating coils, conductors connecting the lagging segments to the second group of selector magnets, a brush engaging said segments in succession and applying signals thereto, means for applying potential to said first group of selector magnets through said make contacts after the brush has engaged all of the leading segments, and means for applying potential to the energizing coil of said clearing relay before the brush again engages any of the leading segments.

.2. In a receiving system for multi-unit equal length codes, a distributor commutator having a signaling segment for each code unit, a first group of printer selector magnets for the leading code units, a second group of printer selector magnets for the lagging code units, a plurality of relays, each having operating and holding coils and two pairs of make contacts, a clearing relay having an energizing coil and break contacts, conductors connecting said holding coils to. a source of potential through said break contacts and one pair of said make contacts, conductors connecting the leading segments of said distributor to said operating coils, conductors connecting the lagging segments to the selector magnets of the second group, a brush engaging said segments in succession and applying signals thereto, means for applying potential to the selector magnets of the first group through the other pair of make contacts after the brush has engaged one of the lagging segments, and means for applying potential to the energizing coil of said clearing relay before the brush disengages the last one of said lagging segments.

3. In a selecting system responsive to multiunit equal length code signals, a receiving distributor having one series of segments individual to the code units and a second series of segments for timing the sequence of operations of the system, a signal storage device including a plurality of self-locking relays corresponding individually to the first few of said code unit segments, selecting magnets arranged in two groups, means whereby the first of said groups is individually controlled by said locking relays subsequent .to the arrival of corresponding code unit signals, and means whereby the second of said groups is individually controlled directly from the remainder of said code unit segments rollowingsaid first few, means including a segmentyof the second series, in circuit with contacts of said relays for energizing selected ones of the selecting magnets, a relay having break contacts for unlocking the first-mentioned relays, and means including another segment of the second series in circuit with the last-mentioned relay- 4. The combination according to claim 3 and including a printer control magnet and a third segment of the second series in circuit therewith.

5. In a receiving system for multi-unit equal length codes, a distributor having segmental components for each code unit, a selector device for each code unit, the devices being .of two groups for the leading and trailing code units respectively, storage .means constituted by a plurality of self-locking relays each having make contacts in circuit with respective ones of said selector devices in the leading group, a signal-controlled energy feeder connectable sequentially through said segmental components firstly to energize selected ones of said relays, and subsequently to energize said selector devices of the trailing group, all in accordance with the selecting code units of received signals, an auxiliary energy feeder means operable subsequently to the locking up of selected ones of said relays for applying potential through the relay make-contacts to their respective selector devices, a relay having break-contacts for unlocking said relays, and means including a circuit independent of said auxiliary feeder means and operable thereafter for momentarily energizing the last-mentioned relay, thereby to unlock the first-mentioned relays.

JAMES A. SPENCER. 

